Possible implantation??

Melinda • TTC #1 with my marine hubby (:
Hi everyone! My cycle has been wacky this month, I'm usually very consistent with having a 28-30 day cycle and ovulating no later than CD14. This month I ovulated CD22 according to my bbt! I'm now at 9dpo (CD31) I'm obviously now expecting a later period due to later ovulation.. But today I've been having brown discharge and at first I had cramps for maybe 5 minutes. No signs of red blood, just light brown spotting. My period was originally due March 27th but now it's due April 5th. Could this be implantation bleeding??? I don't want to test til I know I definitely missed AF! I've been starving lately a few hours after I eat and become full.. And boobs have been sore. I also have had random cramps a few days ago that came and went quickly. All mild cramping, nothing like my AF cramps which I get really bad. I've also NEVER spotted before AF!